Skip-feed mechanism



M r h 1955 H. B. GREENWOOD SKIP-FEED MECHANISM 3 Sheets-Sheet 1 Filed March 10,.1954

} W di? BYZL/aRau/M/y" ATTORNEYS SKIP-FEED MECHANISM Filed March 10, 1954 3 Sheets-Sheet 2 March 1955 H. B. GREENWOOD 2,705,143

SKIP-FEED MECHANISM Filed March 10, 1954 3 Sheets-Sheet 3 INVENTOR BY 66., yuw I l/din ATTORNEYS United States Patent ce 2,705,143

Patented Mar." 29, 1955 time are moved intermittently into and out of sheet engaging position on alternate delivery strokes by operating means actuated by the reciprocating movement of said 2,705,143 th e ir a r id f il rther objects, features, and advantages will SKIP FEED MECHANISM be apparent from the description which follows read in Appicam r t-335 3 i fififi tg i vievi i'iiiiih of the feed 13 Claims. (Cl. 271-44) mechanism shown in Figure 1.

Figure 3 is a partial, shortened end elevational view looking from the right of Figure 1.

Figure 4 is a part sectional, part elevational view on This invention relates to a mechanism for feeding the line44 of Figure 5 with parts cut away.

sheets of relatively stiff material such as cardboard from Figure 5 is a top plan view of a portion of the feed a stack to a processing machine, and more particularly to mechanism shown in Figure 1 and a feeding mechanism which engages and feeds a sheet Figure 6 is a sectional view on the line 66 of Fig only on alternate feed strokes, thus being called a skipure 5.

feed mechanism. Referring first to Figure 1, the inlet end of a printer- The need for skip-feeding arises primarily in conslotter is indicated generally at 1. Full details of the nection with processing machmes which are designed to printer-sl'otter are not shown since they are conventional and form no part of this invention. It is to be underup to a predetermined maximum length in th di e i stood that the term printer-slotter is used by way of exof feed, but which would be able to accommodate longer amp because f h p p s s f this inv nti n the or oversized sheets if fed at a slower rate. The invention {hachihe indicated at 1 could machine P is described with particular relation to a processing mag Processes other than P and Slothhg The c me WhlCh 1s a prmter-slotter of the ty ed in ki prmter-slotter 1 has mltial gripping rolls 3 and 5 to which oxes from cardboard sheets The partlcular prmterph Sheets 6 are Presented y the feeding mechahlsm slotter has a feed platform over whi h h t are indicated generally at 10 to the right of Figure 1. The

rolls of the machine. The platform has a plurality f also serves as a base structure for the feeding mechanism guide grooves therein parallel to the direction of feed. A 0- h P m 1 i provi ed with tWO parallel, unplurality of slides are positioned one in each of said defcut grooves 12 and 13 thefeih eX1 eIldihg normal to grooves, The said lid support sheet engaging means the rolls If and 5 and shown best in Flgures 3, 5 and 6. and are connected to moving parts of the machine in a Support slides 14 h 15 are adiustahly secured in gFOQVeS manner eflecting reciprocation of the slides in timed rela- 12 h 13, reepectlvely, y flh of bolts 16 Countertion to the motion of the processing parts of the machine. Sunk the shdes a threaded Info 11118 17 and 13 The sheet en a in e n are supported on h lid cated, respectively, in the undercut port1ons of grooves 12 below the ta k i a manner causing id means to engage and 13. Welded or otherwise secured transversely on and deliver a sheet from the bottom of the stack to the the ends of pp slides 14 and 15, lg t ly, are initial gripping rolls continuously upon each forward trahsvel'se Support bars 19 and each having bolted stroke of said slide otherwise secured thereto three back-stop supports indi- The feeding mechanism described in the preceding Gated gene-{ally at Each back-Stop E PP F has a paragraph is well known and operates to deliver regular 1 1 3 g 22 and a PPQ 23, as

manner but will improperly process 01' even be clogged by 9f the bOttOm sheet resting 011 platform 11 and the trailtion modifies such known structure by replacing the existi gp g pppr The lprinter-filotten cai' ries a mg sheet engaging means with new sheet engaging means 1 y 8 6mg 8 Own fi lgufie movable vertically below the stack and means actuated W W1 Prevent OrWar eme t of a ut t e by the reciprocating movement of said engag ng means fffi f f d b it h t 6 f th i g Sucht-vertlcal moveinenft 3 lie-lapositi n s h ov fi s c a lid i n Figiii' l to t l ie d iivery i'ii s itioii tion 0 e reclproca mg movemen o e engaging means, with the result that the s heet engaging means gg i ig W111 110W i c i lg- 11 t ltloli Ito and are raised to sheet engaging position only on alternate a W1 8 an P 3 2 7 h g strokes of the slides. Since such modified corstruci gg ig g g g lfigg goals 25 gnaw? Sgt tion feeds only one sheet in the time interval uring t which two sheets would be fcdlwith conventignlal strucif fi g g gg i gg ig 3 1352 22g gegg ci fielg ture, the modified structure wi permit use 0 t e processing maclclline to handle sheets which exceed the limiting g g i h g gg :25 3:13;; agg us t aelz ly geci ifig 217 tggi 5e9- iii gfi g fiigig of the present invention is to received, respectively, in under cut grooves 41 and 43 in an mechanism which tittt tazrzthzte at; a ash 2355322355 comphsh feeding of overslzed sheets at a relatively slow into nuts 37 39 thus connectin feed a an d rate to processing machmes which will not accommodate the feed baris fr movement t hen bolt S 653 a such sheetslfbfed at thinomlalrelauvelty hlgh rate. h tight and for relative movement when the bolts Zr:

fgfigg gg fizi fi ig fig li f to be loosened. It may be noted that ad usting said feed bars quickly and easily installed on the previously described 35 longitudinally 1 8 their Carriers 29, 31 displaces rinte lotte on any other progessing hi having the area of reciprocat on of each feed bar forwardly or a similar continuous feed mechanism, and whlch is also F Y 310118 the 11116 of feed- The term, area f particularly adapted to permit such machines to be quickclprocation the feed bar, as used in the specification ly and easily reconverted to continuous feed. and cla1ms 1s intended to define the space through which A further object of the invention is to provide a skipa given point on the feed bar travels when the feed bar feed mechanism in which sheet engaging means are conreciprocates between its forward and rearward positions. tinually reciprocated along the feed path and at the same A transverse feed bar 45 extends across and is bolted at are provided at their rearward 'printer-slotter, and

, to Figure 1.

angles to the feed bars the feed bars 33 and 35 as shown in Figures 4 and Six strap-spring feeders or sheet engaging members 46 are bolted or otherwise secured at their forward ends to the forward edge of transverse bar 45 and ends with sheet engaging lips 47, all as shown in Figures 4 and 5.

The feed bar carriers 29, 31 are reciprocated in timed relation to the movement of operating parts of the the means for imparting such reciprocating movement will now be described with reference The printer-slotter has a crank wheel 50 rotated in timed relation to the operating parts of the printer-slotter. Wheel 50 is geared to rolls 3 and 5, and carries a crank pin 51. The rotary motion of wheel 50 is used to oscillate a pivot shaft 52 by means of a crank lever consisting of the parallel arms 53 which are secured at one end toshaft 52 and which are connected together at the opposite end by spacing bolt 54. Arms 53 form between them a cam slot in which pin 51 is operatively received to impart oscillating motion to shaft 52. The oscillating motion of shaft 52 is translated into reciprocation of feed bar carrier 29 by means of rocking lever 55 and connecting rod 56. Lever 55 is attached to shaft 52 on the opposite side of arms 53 from wheel 50 so as not to interfere with the movement of pin 51, and rod 56 is pivotally connected at one end to lever 55 and at the other end to an car 57 depending from feed bar carrier 29. Similar lever and connecting rod means (not shown) are provided for feed bar carrier 31 on the opposite side of the printer-slotter so that bars 29 and 31 are reciprocated in unison.

The feed mechanism thus far described accomplishes continuous reciprocation of feeders 46 in timed relation right angles to ,to movement of the operating parts of the printer-slotter.

In a conventional, continuous sheet feeding system, feeders 46 would be arranged to contact and remove the bottom sheet from supporting lips 23 on each forward or delivery stroke of transverse feed bar 45. In the present invention, however, feeders 46 are raised and lowered on alternate delivery strokes so that a sheet is fed only on every other delivery stroke, as will be more fully explained hereinafter. The conventional, continuous feed system delivers sheets at a high rate but can only be used with sheets up to a predetermined maximum length in the direction of feed. Any attempt to use sheets of greater than said maximum length will result in overfeeding. For example, printer-slotter 1 may have a conventional printing roll (not shown) of a circumference such that it will not properly print continuously fed sheets having a dimension in the direction of feed which exceeds about 50 inches. The actual dimensions, of course, may vary with difierent size machines, but for the purposes of explanation, sheets up to 50 inches in the direction of feed, which may be continuously fed, will be called regular size sheets, and those above 50 inches, which require skip feeding, will be called oversized sheets.

The structure for accomplishing the raising and lowering of sheet feeders 46 will now be described with particular reference to Figures 1, 2 and 4 The feed bars 33 and 35 support bearings 61 and 62, respectively, and alshaft 64 is rotatably mounted in said bearings at right 33 and 35. Attached to shaft 64 for rotation therewith are metallic lift earns 66, one cam being located below each strap spring 46 for operative engagement therewith. Feeders 46 have a permanent set or bias such that they will maintain continuous contact with earns 66. Each lift cam has three equally spaced metallic raised portions 68 and a collar 70 of rubber or other non-metallic material which forms threeva'lley portions between the raised portions. The purpose of collar 70 is to avoid the noise which would normally occur if strap springs 46 were permittedto snap down on an upwardly moving metallic portion 68 as earns 66 are rotated to lower the strap springs. In order to accomplish this purpose, the diameter of collar 70 is slightly greater than would be the diameter of a circle tangent to a plane laid across the edgesv of adjacent raised portions 68 so that the strap springs 46 will move down. into contact with the non-metallic colbars 70 instead of into contact with one of the metallic portions '68.

Operativemovementof cams 66 1s provided by rotation of shaft 64 which is'accomplished without the addition of a separate prime mover by utilizing the existing reciprocating motion of feed bars 33 and 35, As shown best in Figure 2, six-toothed ratchet wheel 80 is rigidly secured to the end of shaft 64 by set screw 81, and a pawl carrying lever 82 is journaled on the shaft adjacent wheel 80 for rotation relative thereto. Lever 82 pivotally supports a removable pawl 84 and a spring 86 in contact with the pawl to maintain operative engagement between the pawl 84 and ratchet wheel 80. Spring 86 may be easily dismounted by removing screw 87. As shown best in Figures 1 and 3, the lower end of lever 82 is pivotally connected to a stud collar 88 having a thumb screw 89 by which it is securely attached toward one end of a check rod or link 90. Thumb screw 89 is used for the purpose of allowing quick separation of lever 82 from rod 90, and a stop collar 91 is permanently attached to rod to enable rapid relocation of the lever at its original position along the rod. The distal end of rod 90 is pivotally attached to stationary stud 92. A plate 95 having a plurality of stud-receiving holes 97 is attached to the side of platform 11 for the purpose of providing adjustment of the stationary position of stud 92. It will be seen that holes 97 are indexed in inches to designate the proper hole fora given sheet length. As a matter of convenience, similar indexing (not shown) can be provided on the top of feed bar carriers 29, 31 and on platform 11 adjacent grooves 12 and 13.

Operation The skip-feed mechanism thus described operates in the following manner. Assume that it is desired to feed 61-inch sheets, that is, oversized sheets which would not be properly processed if fed to rolls 3 and 5 on each delivery stroke of feeders 46. Then support slides 14 and 15 with their associated back-stop supports 21 are moved to a position such that when the rear edges of the sheets are supported on lips 23, the forward edges of said sheet will engage feed gates 24. Similarly, feed bars 33 and 35 are adjusted relative to feed bar carriers 29 and 31 so that at the end of the rearward or retracted stroke of the feed bars, as shown in solid lines' in Figures l and 2, sheet-engaging lips 47 of strap springs 46 will be positioned rearwardly of the sheet-stopping edges 22. Stud 92 is positioned in a hole 97 which will locate collar 88 substantially midway along the path of reciprocation of shaft 64. Then, as strap springs are reciprocated between the delivery position shown dotted in Figure 1 and the retracted position shown solid, shaft 64 will be intermittently rotated by virtue of the pawl and ratchet and springs 46 will be oscillated by cams 66 between the sheet engaging position shown solid in Figure 2 and the sheet avoiding position shown dotted. The distance traveled by shaft 64 between the solid and dotted positions shown in Figure l and the length of lever 82 are such that the lever rotates approximately 60 degrees for each single stroke of shaft 64.

Assuming that the parts are in the retracted, sheet engaging positions shown solid in Figure 1, then forward movement to the delivery position shown dotted will cause lever 82 to rotate approximately 60 degrees counterclockwise relative to shaft 64. During such movement shaft 64 will be held against rotation by the frictional contact between springs 46 and cam portions 68 with the result that pawl 84 will slide around ratchet wheel 80 into engagement with the next adjacent ratchet tooth, since the teeth are approximately 60 degrees apart. Now as shaft 64 moves back from the position shown dotted in Figure l to the position shown solid, lever 82 will rotate approximately 60 degrees clockwise relative to the axis of shaft 64. During such rotation, engagement between the pawl and ratchet will force shaft 64 to rotate approximately 60 degrees. Since the raised portions 68 of earns 66 are spaced at approximately degree intervals, such 60 degree rotation will present a-valley portion or collar 70 of each cam to its associated spring 46. The result of this construction is that as springs 46 again reach retracted position they willhave lowered to the sheet avoiding position shown dotted in Figures 2 and 4. Such lowered condition of springs 46 positions their sheet engaging lips 47 below the bottom sheet 6 with the result that no sheet is carried forward on the next delivery stroke of the spring feeders. During such next delivery stroke, rotation of shaft 64 is prevented by frictional contact between springs 46 and cam collars 70 so that pawl 84 will slide approximately 60 degrees around wheel 80 into engagement with the next ratchet tooth. The cycle is completed when springs 46 are again moved rearwardly into retracted 64 is rotated approximately 60 degrees clockwise to move the point of contact between the cams 66 and springs 46 from the valley portion or collar 70 to the next ad acent raised portion 68, so that lip 47 will again be raised to the sheet engaging position shown solid in Figures 1, 2 and 4. Thus it will be seen that spring feeders 46 engage and deliver a sheet 6 to feed rolls 3 and 5 only on alternate delivery strokes.

From the preceding description it will be readily apparent that the skip-feed mechanism of this invention is particularly adapted for use on existing conventional printer-slotters having the adjustable reciprocating feed supporting lips 23. The installation of the skip-feed mechanism is very simply accomplished by substituting sheet feeders 46 for e conventional sheet engaging means, and adding the cam-bearing shaft 64 together with its operating linkage.

It will be further apparent from the preceding description that once the skip-feed mechanism of this invention has been installed on a conventional printer-slotter or on one particularly designed for its reception, it is a simple matter to convert from skip feeding to continuous feeding and vice versa. For example, the mechanism may be converted from skip feeding to continuous feeding by simply disconnecting the rotating mechanism from shaft 64 when the printer-slotter is stopped and cams 66 are oriented to hold sheet feeders 46 elevated in sheet engaging position. The rotating mechanism can, of course, be disconnected at any of its removable connections, but the most complete disconnection would be accomplished by removing ratchet wheel 80 and lever 82 from the end of shaft 64. Conversion back to skip feeding would, of course, be accomplished merely by reconnecting the rotating mechanism.

The skip-feed mechanism as illustrated'and described above is by way of example only, and any changes which might occur to one skilled in the art are contemplated by the present invention, within the scope of the following claims.

Having thus described the invention, what is claimed as new and desired to be secured by Letters Patent is:

1. In apparatus for feeding sheets from a stack, movable sheet engaging means, means for moving said engaging means back and forth along a line of feed between a retracted position and a sheet delivery position, and means actuated by motion of said sheet engaging means toward said retracted position for moving said sheet engaging means substantially normal to said line of feed into sheet engaging position during one movement toward said retracted position and into sheet avoiding position during another movement toward said retracted position.

2. Apparatus for feeding sheets from a stack comprising feed means supported for reciprocation along a feed line, and means for reciprocating said feed means, sheet engaging means supported by said feed means for reciprocation therewith, said sheet engaging'means being movable relative to said feed means in a direction generally and a sheet avoiding position, a rotatable cam cagied by said feed means for supporting said sheet engaging means in said sheet engaging position or in said sheet avoiding position, and means for rotating said cam to support said sheet engaging means in sheet engaging position during one delivery stroke of said feed means along said feed line and in sheet avoiding position during the next delivery stroke of said feed means along said feed line.

3. In a material normal to said feed line between sheet engaging position.

processing machine having movable parts and a material receiving platform with means for supporting one end of said material above said platform, skip-feed mechanism comprising material engaging means movable horizontally between positions rearwardly and forwardly of said supporting means, means position. During such movement shaft between for adjustably connecting said link to said base structure .at a plurality of points spaced along a line parallel to the for moving said engaging means backand forth between. timed relation to movement of said said positions in movable parts, and means actuated by said back and forth movement of said material engaging means for raising said engaging means during one rearward move ment thereof and for lowering said during the next rearward movement thereof.

4. Skip-feed mechanism for feeding sheets from a stack,

said mechanism comprising a stationary base structure,

a feed member reciprocatably supported by said base supported by said movable relative thereto, means for feed member along a a sheet avoiding position relative to the rear edge of the end sheet, said last named means comprising a cam rotatably carried by feed member, said cam having a raised portion and a valley portion, said sheet engaging mem; er being continuously urged into contact with said cam so that when said sheet engaging member is in contact with one of said cam portions the sheet engaging mem: ber is in said sheet engaging position and when said sh'ee't engaging member is cam portions said sheet engaging member is in said sheet avoiding position, and means for rotating said cam so that said sheet engaging member will be in contact with said raised portion during one delivery stroke of said feed member and in contact with said valley portion;

during the next delivery stroke of said feed member.

5. Skip-feed mechanism as claimed in claim 4 in which said cam has a shaft extending substantially transverse to the line of reciprocation of said feed member, and said means for rotating said cam comprise a lever rotatably journalled on said shaft, a pawl member operatively associated with each other, one of said pawl and ratchet members being rotatable with said cam, and the other of said being rotatable with said lever, and means connected to said lever at a point to one side of the line of the reciprocation of said shaft for substantially restraining said point from movement parallel to the line of reciprocation of said shaft but permitting substantial movement of said point in a direction normal to the line of recipro cation of said shaft.

6. Skip-feed mechanism as claimed in claim 5 in which said raised portion of said cam is metallic and said valley portion of said cam is non-metallic.

7. Skip-feed mechanism as claimed in claim 5 in which said means connected to said lever at a point to one side of the line of reciprocation of said shaft comprises a link pivotally connected adjacent one of its ends to said lever and pivotally connected adjacent the other of its ends to said base structure.

8. Skip-feed mechanism as claimed in claim 5 in which said means connected to said lever at a point to one side of the line of reciprocation of said shaft comprises a link pivotally connected 40 the said lever and pivotally conneeted to said base, structure, said pivotal connection said link and said base structure including means line of reciprocation of said feed member.

9. Skip-feed mechanism for feeding sheets from a stack, said mechanism comprising a reciprocatably mounted feed member, a strap spring connected at one end to said feed member and having a sheet engaging lip remote from said one end, a cam rotatably supported by said feed member, means for reciprocating said feed member so that said sheet engaging lip moves back and forth between a retracted position rearward of the rear edge of said stack and a delivery position forward of the rear edge of said stack, said strap spring being biased to maintain contact with said cam, said cam aving a raised portion for moving said strap spring into a position in which said lip will engage the rear edge of the end sheet in said stack during the delivery stroke of said feed member, said cam also having a valley portion for positioning said strap spring with its sheet engaging lip out of engagement with the rear edge of engaging means line of feed engaging member moves back and in contact with the other of said member and a ratchet pawl and ratchet members the end sheet in said stack during the delivery stroke of said feed member, and means for rotating said cam in timed relation to the reciprocation of said feed member so that on some delivery strokes said raised portion will be in contact with said strap spring and on other delivery strokes said valley portion will be in contact with said strap spring.

10. In a machine for processing sheets of relatively stiff material and having a sheet receiving platform, skipfeed mechanism comprising a plurality of sheet supporting members, means supporting said members on said platform at a position spaced from said machine, said supporting members each having a sheet supporing lip projecting forwardly toward said machine to form a surface for supporting the rear edge of a stack of sheets elevated from the top of said platform, a plurality of feed members reciprocatably supported by said platform for movement toward and away from said machine along the line of feed, a bar connected to said feed members and extending transversely of the line of feed, a plurality of strap springs each connected at one end to said bar and having a sheet engaging lip remote from said one end, a shaft rotatably supported by said feed members and having its axis transverse to the line of feed, a plurality of cams rigidly secured to said shaft, each of said cams being positioned beneath a different one of said strap springs and each of said strap springs being biased into engagement with its respective cam, said strap springs being offset from said sheet supporting members whereby the strap springs may be moved rearwardly and forwardly past said sheet supporting members, means for reciprocating said feed members so that said sheet engaging lips move back and forth between a retracted position behind said sheet supporting lips and a delivery position forward of said sheet supporting lips, each of said cams having at least one raised portion for moving said strap springs upwardly so that when said sheet engaging lips are in said retracted position they will be higher than the rear edges of said sheet supporting lips, each of said cams also having at least one valley portion for supporting said strap springs in a position in which said sheet engaging lips are lower than the rear edges of said sheet supporting lips, and means for rotating said shaft so that on one delivery stroke of said feed members said raised portion of each cam will be in contact with its respective strap spring and on the next delivery stroke said valley portion of each cam will be in contact with its respective strap spring lL Skip-feed mechanism as claimed in claim in a a pawl on said carrier constantly urged into contact with said ratchet wheel, and means connected to said carrier at a point to one side of the line of reciprocation of said shaft for substantially restraining said point from movement parallel to the line of reciprocation of said shaft and permitting substantial movement of said point in a direction normal to the line of reciprocation of said shaft.

12. Skip-feed mechanism as claimed in claim 11 in which said sheet supporting members are mounted on said platform for adjustment toward and away from said machine, said means for reciprocating said feed members includes means for adjusting the area of reciprocation of said feed members toward and away from said machine, and said means connected .to said pawl carrier comprises a link pivotally connected adjacent one of its ends to said carrier, a plate attached to said platform and having a plurality of holes spaced along a line parallel to the line of reciprocation of said shaft, and a pivotal connection formed adjacent the other end of said link and including a stud selectively secured in one of said holes.

13. Skip-feed mechanism for feeding sheets from a stack, said mechanism comprising a sheet engaging member reciprocatable along a feed line generally parallel to the sheets in said stack, said sheet engaging member being oscillatable in a direction generally normal to said feed line, means for reciprocating said sheet engaging member along said feed line between a retracted position rearward of the rear edge of said stack and a delivery position forward of the rear edge of said stack, and means actuated by said reciprocating motion of said sheet engaging member for oscillating said sheet engaging member in said generally normal direction so that on one delivery stroke said sheet engaging member will be operative to engage and deliver a sheet and on the next delivery stroke said sheet engaging member will be inoperative to deliver a sheet.

References Cited in the file of this patent UNITED STATES PATENTS 

